As the number of serious incidents involving drunk and violent travelers increases, airlines are being forced to physically restrain an increasing number of disorderly passengers, according to the International Air Transport Association.

Statistics released Tuesday by the industry's main trade group show a 50 percent rise last year to 169 passengers who were forcibly confined for behavior ranging from verbal and physical abuse to life-threatening actions -- the most serious of which involved attempts to enter the cockpit.

The annual tally by IATA of bad form comes as examples of extreme in-flight incidents grab headlines and flood social media. These have included the escort by fighter jets in May of an American Airlines plane to Honolulu after a passenger, who appeared to be intoxicated, attempted to breach the cockpit door.

In some cases, the conflicts erupting in airplanes have hurt carriers' own reputations, such as when security personnel dragged a passenger from a United Airlines plane because he refused to relinquish his seat. Chief Executive Officer Oscar Munoz apologized for how the company handled the episode.

The number of incidents involving disorderly passengers has risen in recent years, with IATA saying in the past that airlines are increasingly having to navigate local laws to bring prosecutions for offenses and crews have to be trained on how to handle violence.

While the total number of reported incidents last year actually fell by almost 10 percent to 9,837, the portion that were deemed a higher risk increased from 2015. Here's what unruliness looked like last year:

An incident was reported every 1,434 flights

12 percent included physical assault, up from 11 percent a year earlier

About a third of all incidents, involving 3288 passengers, were related to intoxication, including 444 registered as cases that escalated physically

IATA said the more than half of safety rules-related offenses involved passengers smoking on board, either in the main cabin, or more likely, in the bathrooms.

The figures accounts for 190 of the world's airlines so "are likely to significantly underestimate the extent of the problem," IATA's assistant director for external affairs Tim Colehan said in Geneva.